Designing Bi‐In2O3 Nanoflower Catalysts for Enhanced Performance of Electrochemical CO2 Reduction to Formate

Electrochemical CO2 reduction (ECO2RR) is capable of converting CO2 into a wide range of value‐added products under relatively mild conditions. Electrocatalyst with high selectivity and activity is crucial for high efficient ECO2RR. Herein, Bi‐In2O3 nanoflower catalysts with different metal ratios synthesized by wet chemical method are used for ECO2RR to produce formate. The results indicate that the hydrogen evolution activity of the Bi‐In2O3 catalysts during ECO2RR is suppressed at a low level and the activity and selectivity of formate production is related to the ratio of Bi to In content in the catalysts. The optimized Bi‐In2O3 catalyst with the ratio of Bi6In94 can achieve a high formate Faradaic efficiency (FEformate) over 80% under a wide potential range from ‐0.7 V to ‐1.2 V vs. RHE, with the maximum value of 88.1% at ‐0.7 V vs. RHE. Meanwhile, the highest formate partial current density reaches 47.7 mA cm‐2 at ‐1.2 V vs. RHE and the current density and Faradaic efficiency remain stable during the 10 h stability test. The enhanced formate formation on Bi‐In2O3 NF can be attributed to the synergistic effect between Bi and In according to the characterizations of the Bi‐In2O3 NF.